This invention relates to the production of hydrocyanic acid (HCN) from carbon monoxide (CO) and ammonia (NH.sub.3). More specifically, this invention relates to the production of HCN from CO and NH.sub.3 in the presence of a catalyst comprising a noncarbonaceous, porous catalyst support, a catalytic Group VIII metal which is at least one of Fe, Ni, Co and Ru, and carbon, wherein the metal is disposed on the pore surfaces of the support and is randomly bonded to the carbon.
Belgian Patent No. 869,185 describes a novel catalytic material for use in the production of methane which comprises carbon fibers containing small nodules of iron or other Group VIII metals. This material is formed by contacting the Group VIII metal with a mixture of CO and hydrogen at an elevated temperature to cause deposition of carbon through the disproportionation of CO. When this material is contacted with hydrogen at an elevated temperature, the carbon in the material reacts with hydrogen to form methane.
U.S. Pat. No. 1,626,848, to Liebknecht, issued May 3, 1927, discloses a process for the production of HCN by reacting CO and NH.sub.3 in the presence of a catalyst comprising a porous, nonacid charcoal. This porous, nonacid charcoal is an activated charcoal which may be used alone or in combination with other inert or catalytic substances such as metallic oxides. These oxides may be admixed with the charcoal or the charcoal may be impregnated or coated with the metallic oxide.
U.S. Pat. No. 1,751,933, to Lindner, issued Mar. 25, 1930, discloses a process for producing HCN by contacting NH.sub.3 and CO with a catalyst comprising an iron carbide. This catalyst may be used alone or in conjunction with at least one of molybdenum, manganese, tungsten, cerium, titanium or copper, either in the free or combined state.
U.S. Pat. No. 1,598,707, to Bredig, et al., discloses a process for the production of HCN by reacting NH.sub.3 and CO in the presence of a Group IVA or B carbide catalyst. U.S. Pat. No. 1,610,035, also to Bredig, et al., discloses a process for the production of HCN by reacting NH.sub.3 and CO in the presence of a vanadium oxide. U.S. Pat. No. 1,627,144, to Bredig, et al. discloses a process wherein HCN is produced by the reaction of CO and NH.sub.3 in the presence of Group III, IV, V and VI metal oxides. U.S. Pat. No. 1,634,735, to Bredig, et al., discloses a process for the production of HCN acid by reacting NH.sub.3 and CO in the presence of a rare earth metal oxide catalyst.
As these references indicate, the formation of HCN by the reaction of CO and NH.sub.3 in the presence of a catalyst has been known since the early 1900's. Although this reaction has the advantage of using low-cost materials as reactants, these early processes suffer from several limitations which are obviated or minimized by the process of the present invention. These limitations include the use of catalysts composed of materials, such as vanadium, which are relatively expensive. Also, catalysts which employ less expensive materials frequently result in inferior yields. In addition, previous catalysts often could not be recycled or displayed very limited life spans.
It was due in part to these limitations that the more recent processes produce HCN by reacting NH.sub.3 with methane. Although this reaction may result in greater yields than the previous processes using NH.sub.3 and CO, this reaction has the disadvantage of using an expensive component, i.e. methane, which has steadily increased in price to obtain a compound which relatively has maintained a low cost.